1. Field of the Invention
The present invention relates to a deposition mask, and more particularly, relates to a deposition mask that makes it possible to deposit a thin-film pattern having a uniform thickness by eliminating effects on film formation by a deposition shadow that is caused by the edge of an opening through which a deposition material passes.
2. Description of Related Art
A conventional deposition mask is formed of three metal layers including a thin opening pattern formation layer, a relatively thick support layer, and a bonding layer for bonding the opening pattern formation layer and the support layer, the opening pattern formation layer, support layer and bonding layer being etched to form a through-opening that extends through these layers (see, for example, JP 2004-183024 A).
In this case, the opening pattern formation layer and the support layer are etched using different resist patterns, the opening pattern formation layer is provided with an opening pattern having a minimum width, and the support layer is provided with a through-hole having a width greater than that of the opening pattern.
However, in such a conventional deposition mask, an opening pattern is formed in a through-hole without considering effects on film formation by a deposition shadow that is defined by the thickness of a support layer and the maximum angle of incidence of a deposition material to a mask surface. Accordingly, if the alignment of resist patterns that form the opening pattern and the through-hole deviates, the opening pattern may be partially caught in the deposition shadow part, so that a thin-film pattern having a uniform film thickness cannot be formed on a substrate.
Thus, for coping with the abovementioned problem, the present invention provides a deposition mask that makes it possible to deposit a thin-film pattern having a uniform thickness by eliminating effects on film formation by a deposition shadow that is caused by the edge of an opening through which a deposition material passes.